1. Field of the Invention
The present invention relates generally to a method for predicting the reaction characteristics of molecules. More specifically, the invention relates to a molecular reaction characteristic predicting method for predicting a correlation characteristic between reaction characteristics of a plurality of molecules, and a reaction characteristic predicting map and computer-readable storage medium.
2. Related Background Art
In the development of a medicine, the prediction of activity and the design of the medicine are carried out. That is, a correlation between the structures of the ligand and an acceptor and/or the interaction therebetween and the pharmacological activity of the medicine on organisms is examined, and it is predicted whether the medicine to be designed has a desired activity, so that the medicine is designed.
In the field of synthetic chemistry, the prediction of reactivity and the design of synthesis are carried out. That is, a correlation between the structures of reactants and/or the interaction between the reactants and the reactivity thereof is examined, and it is predicted whether a sufficient amount of supposed reaction product can be obtained, so that the optimum synthetic route is designed.
In the field of development of medicines, the cooperative molecular field analysis (CoMFA) method is conventionally known as a method for predicting the activity characteristics of ligand molecules (see, e.g., R.D.III Cramer, et al., J. Am. Chem. Soc., 1988, 110, 5959).
In the CoMFA method, a CoMFA field is produced to give the three-dimensional expression of a chemical structure of ligand molecule. The CoMFA field is derived by forming, e.g., a rectangular parallelepiped-shaped region surrounding a molecule, the activity characteristic of which is to be predicted, considering lattice points, which are distributed in the surrounding region in the form of a lattice, as probe points, and putting probe atoms at the respective probe points to calculate energy of the interaction between the probe atoms and the components of the molecule, such as substituents.
In the CoMFA method, it is assumed that a portion occupying a major part of a molecule, the reaction characteristic of which is to be predicted, is a common skeleton serving as a common portion, and the substituted portions of molecules having a common skeleton are substituted by various substituents. On the basis of the correlation characteristics of the obtained CoMFA, the presence of similarity between the activity characteristics of the molecules having the common skeleton is determined.
However, in the CoMFA method, it is assumed that the molecules have the common skeleton, and when the prediction of the activity characteristic of a certain molecule is intended, the presence of similarity between activity characteristics is determined only between the certain molecule and another molecule having a common skeleton with the certain molecule.
Thus, it is not possible to determine the presence of similarity between reaction characteristics of molecules, which have quite different sizes and which do not have any common skeleton.
In addition, in the CoMFA method, a molecule, the reaction characteristic of which is to be predicted, is not decomposed into minute sites to derive characteristic values for each site, and one CoMFA field is obtained as the whole molecule. Therefore, it is not known how each of the sites of the molecule contributes to the reaction, so that it is not possible to accurately predict and consider the reaction characteristics of the molecule.
Moreover, in the CoMFA method, the rectangular parallelepiped surrounding the overlapped ligand molecules is different in accordance with the size of a target ligand molecule group, so that there is a limit that the obtained characteristic value depends on the target ligand molecule group.
In addition, the CoMFA method is applied to the prediction of activity and the design of a medicine in the development of the medicine, so that the CoMFA method can not be applied to the prediction of reactivity and the design of synthesis in the field of synthetic chemistry. There is no reaction characteristic predicting method serving as a guide to the prediction of reactivity and the design of synthesis in the field of synthetic chemistry and as a guide to the prediction of activity and the design of a medicine in the development of the medicine.